When one Reddit user suffered a herniated disk in his neck that mangled a nerve in his left arm, he missed six months of work and was paid close to just half his normal take-home pay.

But his $15,000 emergency fund saved the day.

The 36-year-old Canadian IT consultant said the medical emergency would have cost him somewhere around $20,000 in lost wages and life expenses. “Think to yourself, could you live without $20K of your take home salary?” he wrote. “I live alone with no kids so I could, barely.”

He said he was lucky because he had his own safety net and tailored it to his needs.

Not everyone can afford putting away extra money in an emergency fund. An analysis of Federal Reserve data from earlier this week found 41% of households could not cover a $400 emergency expense using cash, a slight improvement from 44% last year.

But some have put a little aside every month, and it has paid off. “My emergency fund just saved me, my wife and my baby from going cold due to a central heating boiler failure,” another Reddit commenter said, adding he was working toward a fund filled with the equivalent of six-months of income in a mixture of cash and other investments.

See: Try these 10 easy things to improve your finances now

Another savvy saver said $10,000 in savings helped after a layoff. Yet another commenter said after his company moved operations overseas and he was left without a job, his savings helped him live comfortably. “While it’s painful having to dip into savings, it took one of my many worries away,” he wrote, “enabling me to get back into the right head space to start the daunting process of applying for jobs again.”

All too often Americans without emergency funds are turning to credit cards or borrowing from family and friends, and when they can’t pay all their bills, rent, mortgages or utility bills are the ones that are left unpaid. According to another study, only 39% of Americans say they have the money to cover a $1,000 emergency room visit or car repair, personal finance site Bankrate.com found.

Also see: How much do I really need in my emergency fund?

Not everyone in the Reddit thread was sold on having an emergency fund. One user said everyone who’s insisted on an emergency fund filled with cash could have used a credit card until the assets they needed were liquidated. His fund is in the stock market, and he doesn’t mind the risk this may pose should he suddenly find himself without a job.

“So there’s little to no use for a large cash [emergency fund] when you could just put it into a low risk fund, pay any emergencies with a credit card, and liquidate the fund to pay the bill,” he said.

Alessandra Malito is a personal finance reporter based in New York. You can follow her on Twitter @malito_ali.